Glomerulonephropathy associated with Dirofilaria immitis (heartworm) is relatively frequent in infected dogs. Given the importance and the scarcity of studies focused on its prevalence and diagnosis, the objective was to determine the prevalence of
proteinuria and functional indicators of glomerular filtration rate in dogs with
heartworm disease and discuss its utility in the detection of renal impairment. Sera and urine from 47 infected dogs were analyzed in a reference laboratory.
Urea,
creatinine,
plasma proteins and serum
symmetric dimethylarginine (SDMA) were analyzed in sera, while the UPC ratio was performed in urine. Dogs were further evaluated for the presence/absence of microfilariae, pulmonary and systemic
hypertension, and the parasite burden was assessed. The results showed that 19.1 % of dogs showed
proteinuria (UPC > 0.5) and 17 % showed borderline
proteinuria (UPC 0.2-0.5).
Creatinine and SDMA were high (>1.8 mg/dl and ≥18 μg/dl, respectively) in 4.2 % of dogs. UPC ratio was significantly increased in dogs with high parasite burden and in dogs with microfilariemia (p < 0.05). Dogs with
pulmonary hypertension showed higher increases in
proteinuria as well, which was probably due to the chronicity of the
infection. No significant differences were found in serum and urine values regarding systemic blood pressure. Despite the limitations of this study,
proteinuria/borderline
proteinuria was present in 36.2 % of dogs with
heartworm disease, and this may be due to glomerular disease. Therefore, the detection of
proteinuria, along with other renal
biomarkers in the diagnostic protocols, could help identify kidney alterations or risk of renal damage in
heartworm disease.